package keypair;

//----------------------------------------------------------------------------
//$Id: GnuRSAKey.java,v 1.4 2005/10/06 04:24:16 rsdio Exp $
//
//Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
//
//This file is part of GNU Crypto.
//
//GNU Crypto is free software; you can redistribute it and/or modify
//it under the terms of the GNU General Public License as published by
//the Free Software Foundation; either version 2, or (at your option)
//any later version.
//
//GNU Crypto is distributed in the hope that it will be useful, but
//WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//General Public License for more details.
//
//You should have received a copy of the GNU General Public License
//along with this program; see the file COPYING.  If not, write to the
//
// Free Software Foundation Inc.,
// 51 Franklin Street, Fifth Floor,
// Boston, MA 02110-1301
// USA
//
//Linking this library statically or dynamically with other modules is
//making a combined work based on this library.  Thus, the terms and
//conditions of the GNU General Public License cover the whole
//combination.
//
//As a special exception, the copyright holders of this library give
//you permission to link this library with independent modules to
//produce an executable, regardless of the license terms of these
//independent modules, and to copy and distribute the resulting
//executable under terms of your choice, provided that you also meet,
//for each linked independent module, the terms and conditions of the
//license of that module.  An independent module is a module which is
//not derived from or based on this library.  If you modify this
//library, you may extend this exception to your version of the
//library, but you are not obligated to do so.  If you do not wish to
//do so, delete this exception statement from your version.
//----------------------------------------------------------------------------

import java.math.BigInteger;
import java.security.Key;
import java.security.interfaces.RSAKey;

/**
* <p>A base asbtract class for both public and private RSA keys.</p>
*
* @version $Revision: 1.4 $
*/
public abstract class RsaKey implements Key, RSAKey {

// Constants and variables
// -------------------------------------------------------------------------

private static final long serialVersionUID = -3818079750139280582L;

/** The public modulus of an RSA key pair. */
private final BigInteger n;
/** The public exponent of an RSA key pair. */
private final BigInteger e;

// Constructor(s)
// -------------------------------------------------------------------------

/**
 * <p>Trivial protected constructor.</p>
 *
 * @param n the public modulus <code>n</code>.
 * @param e the public exponent <code>e</code>.
 */
//protected GnuRSAKey(BigInteger n) {
protected RsaKey(final BigInteger n, final BigInteger e) {
   super();

   this.n = n;
   this.e = e;
}

// Class methods
// -------------------------------------------------------------------------

// Instance methods
// -------------------------------------------------------------------------

// java.security.interfaces.RSAKey interface implementation ----------------

@Override
public BigInteger getModulus() {
   return getN();
}

// java.security.Key interface implementation ------------------------------

@Override
public String getAlgorithm() {
   return Registry.RSA_KPG;
}

/** @deprecated see getEncoded(int). */
@Deprecated
@Override
public byte[] getEncoded() {
   return getEncoded(IKeyPairCodec.RAW_FORMAT);
}

@Override
public String getFormat() {
   return null;
}

// Other instance methods --------------------------------------------------

/**
 * <p>Returns the modulus <code>n</code>.</p>
 *
 * @return the modulus <code>n</code>.
 */
public BigInteger getN() {
   return n;
}

/**
 * <p>Returns the public exponent <code>e</code>.</p>
 *
 * @return the public exponent <code>e</code>.
 */
public BigInteger getPublicExponent() {
   return getE();
}

/**
 * <p>Same as {@link #getPublicExponent()}.</p>
 *
 * @return the public exponent <code>e</code>.
 */
public BigInteger getE() {
   return e;
}

/**
 * <p>Returns <code>true</code> if the designated object is an instance of
 * {@link RSAKey} and has the same RSA parameter values as this one.</p>
 *
 * @param obj the other non-null RSA key to compare to.
 * @return <code>true</code> if the designated object is of the same type and
 * value as this one.
 */
@Override
public boolean equals(final Object obj) {
   if (obj == null) {
      return false;
   }
   if (!(obj instanceof RSAKey)) {
      return false;
   }
   final RSAKey that = (RSAKey) obj;
   return n.equals(that.getModulus());
}

// abstract methods to be implemented by subclasses ------------------------

public abstract byte[] getEncoded(int format);
}
